Non-coated automobile trim members are being popularized for the purpose of reducing the production costs, for which there is increasing a great demand for materials having good characteristics of outward appearance and a quiet feel while preventing light reflection. In addition, the requirements of safe and economical materials are being on a higher level, and inexpensive materials with good impact resistance are desired.
As the materials of automobile trim members, much used are inexpensive, popular propylene-based resins. It is known that addition of styrene-based elastomers to propylene-based resins is effective for improving the impact resistance (room temperature Izod impact strength) of the resins. However, styrene-based elastomers are expensive and are problematic in that the moldings comprising them shall have an increased degree of surface gloss. Moreover, adding a large amount of rubber components to propylene-based resins for the purpose of improving the impact resistance of the resins is further problematic in that the scratch-whitening resistance of the resin moldings is poor.
On the other hand, known are molding materials having good low-temperature impact resistance. For example, disclosed are resin compositions comprising a crystalline propylene-ethylene block copolymer and an ethylene-.alpha.-olefin copolymer as produced in the presence of a metallocene catalyst (see Japanese Patent Application Laid-Open (JP-A) Hei-7-145272, JP-A Hei-7-145298); resin compositions comprising a propylene-based resin and an ethylene-butene-1 copolymer having a relatively large butene-1 unit content (the copolymer is produced substantially in the presence of a metallocene catalyst) (see JP-A Hei-6-192506, JP-A Hei-7-18151); and resin compositions comprising a propylene-based resin and an ethylene-octene-1 copolymer having a relatively large octene-1 content (the copolymer is produced substantially in the presence of a metallocene catalyst) (see International Patent Application Laid-Open No. 94-6859).
Though having good low-temperature impact resistance, those resin compositions are still defective in that their moldings often have uneven gloss and poor scratch-whitening resistance.